A modeling approach for orthogonality of comprehensive two-dimensional separations

Area of Science:

• Analytical Chemistry
• Chromatography

Background:

• Comprehensive two-dimensional separations (C2DS) require robust methods for evaluating orthogonality.
• Existing methods often focus on bin coverage, neglecting accurate peak retention data.

Purpose of the Study:

• To develop a novel, quantitative method for assessing the orthogonality of C2DS.
• To provide a more accurate evaluation of 2D separation performance by considering peak distribution and retention times.

Main Methods:

• Developed a method dividing orthogonality into peak coverage (C(pert)) and 2D distribution correlation (C(peaks)).
• Utilized bin occupation and linear regression on normalized retention times ((1)t(R), (2)t(R)) for quantitative assessment.
• Simulated comprehensive two-dimensional gas chromatography (GC × GC) using the Abraham solvation parameter model.

Main Results:

• The proposed method quantifies orthogonality from 0 (correlated) to 1 (orthogonal).
• Simulations with 225 compounds on different column sets demonstrated the method's effectiveness.
• Results showed the method provides a reasonable assessment of 2D separation performance in GC × GC.

Conclusions:

• The novel method offers a more accurate evaluation of C2DS orthogonality by considering peak distribution.
• This approach can be used to optimize experimental conditions for C2DS, particularly in GC × GC.
• The method is advantageous as it relies on separation properties and avoids imposed limitations.